Simple free guestbook service which allows site visitors to post public and private comments (the latter will only be visible to the guestbook owner).
Guestbook Depot guestbooks are easy to install. How easy? Just fill in a simple form with your email address and a password, and you will get code emailed to you to put in your web page. Once you paste the code into your page, just click the “configure guestbook” link in your guestbook, setup your guestbook the way you like it, and you’re done. You don’t need any complicated CGI or database access from your ISP.